CHEMICAL ABUNDANCES OF RR LYRAE STARS IN THE GLOBULAR-CLUSTER M4

Authors
CLEMENTINI G MERIGHI R GRATTON R CARRETTA E
Citation
G. Clementini et al., CHEMICAL ABUNDANCES OF RR LYRAE STARS IN THE GLOBULAR-CLUSTER M4, Monthly Notices of the Royal Astronomical Society, 267(1), 1994, pp. 43-50
Citations number
29
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Monthly Notices of the Royal Astronomical Society → ACNP
ISSN journal
00358711
Volume
267
Issue
1
Year of publication
1994
Pages
43 - 50
Database
ISI
SICI code
0035-8711(1994)267:1<43:CAORLS>2.0.ZU;2-Q
Abstract
High-resolution spectra (R = 15 000-25 000) of three RR Lyrae stars in the globular cluster M4 are used to perform a chemical abundance anal ysis of these horizontal branch stars. We obtain a metal abundance of [Fe/H] = -1.4 +/- 0.2; alpha-elements (Mg and Ti) are overabundant by 0.6 dex. These results are in good agreement with [Fe/H] estimates fro m the DELTAS index and with abundance determinations from high-resolut ion spectra of giants and blue horizontal branch stars.